2118
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4248
- Proper Divisor Sum (Aliquot Sum)
- 2130
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 704
- Möbius Function
- -1
- Radical
- 2118
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 32
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Number of 5-line partitions of n.at n=13A001452
- Numbers k such that k^4 can be written as a sum of four positive 4th powers.at n=8A003294
- Number of points on surface of octahedron; also coordination sequence for cubic lattice: a(0) = 1; for n > 0, a(n) = 4n^2 + 2.at n=23A005899
- Numbers n such that n^32 + 1 is prime.at n=41A006315
- Number of nonzero elements in the character table of the symmetric group S_n.at n=10A006908
- Coordination sequence T2 for Zeolite Code LEV.at n=34A008128
- a(0) = 1, a(n) = n^2 + 2 for n > 0.at n=46A010000
- Fibonacci sequence beginning 1, 5.at n=14A022095
- Index of 5^n within sequence of numbers of form 2^i * 5^j.at n=42A022334
- a(n) = least m such that if r and s in {h/(1 + h^2): h = 1,2,...,n} satisfy r < s, then r < k/m < s for some integer k.at n=51A024828
- Positions of record values in A030727.at n=41A030732
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 46.at n=0A031544
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 46.at n=1A031724
- Numbers k such that A102489(k) is divisible by k.at n=13A032563
- Multiplicity of highest weight (or singular) vectors associated with character chi_19 of Monster module.at n=33A034407
- Limit of the position of the n-th partition into parts 5k+2 or 5k+3 in the list of all integer partitions sorted in reverse lexicographic order, for integers == 2 (mod 5).at n=45A035407
- Limit of the position of the n-th partition into parts 5k+2 or 5k+3 in the list of all integer partitions sorted in reverse lexicographic order, for integers == 3 (mod 5).at n=34A035408
- Trajectory of 3 under map n->29n+1 if n odd, n->n/2 if n even.at n=14A037112
- Numbers k such that 2047*2^k+1 is prime.at n=10A037177
- Numbers k such that string 1,4 occurs in the base 7 representation of k but not of k-1.at n=49A044149